Method for improving heat exchange calculation performance of steam generator in sodium-cooled fast reactor system program

Abstract

The invention discloses a method for improving the heat exchange calculation performance of a steam generator in a sodium-cooled fast reactor system program, which comprises the following steps: dividing a sodium-cooled fast reactor direct-current steam generator by adopting a fixed grid method, determining the grid division of a steam generator thermal component by adopting the fixed grid method,and calculating the CHF generation position. And judging the heat exchange mode of each grid, and respectively calculating the heat exchange coefficient of each grid according to the working conditions of single-phase liquid heat exchange, nuclear boiling, membrane boiling and superheated steam. And on the basis of the fixed grid, using the CHF movable boundary model for carrying out grid division on the control body with the CHF phenomenon again, and recalculating the heat exchange coefficients of the upper heat component and the lower heat component. Setting boundary conditions, repeating the steps, calculating the heat exchange coefficient of the next time step of each grid, and finally obtaining the heat exchange amount of the steam generator at each moment. According to the method, the heat exchange calculation precision of the once-through steam generator in the analysis program of the sodium-cooled fast reactor system is guaranteed, and the solving speed of the reactor numerical calculation program is increased.

Description

technical field [0001] The invention belongs to the technical field of nuclear reactor system safety analysis and calculation, and in particular relates to a method for improving the heat transfer calculation performance of a steam generator in a sodium-cooled fast reactor system program. Background technique [0002] Due to the good heat-carrying performance of the coolant, high thermal inertia, and high temperature level of the sodium-cooled fast reactor, once-through steam generators are generally used to reduce the size of the reactor and improve the economy. The tube side of the three-circuit once-through steam generator is water, heated by liquid sodium in the second circuit, and the heat exchange modes with the wall surface include supercooled water convection, subcooled boiling, nucleate boiling, film boiling and superheated steam convection. The heat transfer coefficients of each mode are very different, especially the nucleate boiling and film boiling around the CH...

AI Technical Summary

Problems solved by technology

At the same time, the moving boundary method can reduce the number of grids and improve the calculation efficiency, but the moving boundary method is not suitable for system analysis programs

[0004] The once-through steam generator in the sodium-cooled fast reactor system analysis program still uses the traditional fixed grid method to calculate heat transfer, and it is difficult to achieve both calculation efficiency and stability of calculation results

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